Characteristics of tidal current and residual currentin the Qiongzhou Straits in period between end of winter and beginning of spring

From Februarg.26 to March 6,1995, the currents on 15 stations between Xinghai and Sitang are measured.The characteristics of the currents are as follows:The speeds of flood current are larger than ebb current.The maximum flood speed is 172 cm/s,the maximum ebb speed is 142 cm/s;the speed of mean residual current on north 6 stations is 18.4 cm/s.The speed of mean residual current on middle 3 stations of the straits is 18.3 cm/s.The speed of mean residual current on south 6 stations is 10.2 cm/s.The directions of residual currents are in range W-S on northern and middle stationss,and in range N-NE on southern stations, because of the influence of the topography.This paper has used a model to calculate the tidal currents in the straits.The sum of the water amount passing through the west section (Dengloujiao-Yubaojiao) is 4.73×10¹⁰m³ (by ebb current).and is 4.29×10¹⁰m³ (by flood tide).The sum of the water amount passing through the east section (Dongying-Longtangzhen) is 5.22×10¹⁰m³ (by ebb current) and is 1.90×10¹⁰m³ (by flood tidal current).The net amounts are 0.43×10¹⁰m³ (west section) and 0.32×10¹⁰m³ (east section).The direction of the net transportation points toward west.